JP2014512735A - Virtual aggregation of fragmented wireless spectrum - Google Patents

Abstract

Method and apparatus for aggregating spectra. Here, by modulating each portion of the data stream into each remote block of the spectrum, multiple remote blocks of the spectrum can be configured as one continuous virtual block of the spectrum, and this modulated The data rate associated with the portion is compatible with the available bandwidth of the remote spectral block being modulated.

Description

  The present invention relates generally to communication networks, and more particularly, but not exclusively, to satellite and microwave-based point-to-point communication and backhaul links.

  Conventional wireless systems assume that a continuous block of spectrum is available with a bandwidth proportional to the amount of data transmitted. Transmission systems are therefore often designed for worst-case bandwidth requirements using normal or average use cases, and in some cases require less bandwidth (ie spectrum) Sometimes.

  In satellite communication systems and other point-to-point communication systems, the available spectrum assigned to the customer may become fragmented over time, which may result in unallocated space between the allocated spectrum blocks. Use blocks occur. If the unused spectrum block is too small, reassign the spectrum between customers or merge the unused block of spectrum into a single spectrum region from the existing spectrum assignment to the new spectrum assignment. It is necessary to “move” the customer. Unfortunately, such a reassignment causes a great deal of confusion.

  Various deficiencies in the prior art are addressed by the spectrum aggregation system, method and apparatus of the present invention, where each portion of the data stream is modulated into separate blocks of the spectrum, Multiple remote blocks of spectrum can be configured as one continuous virtual block of spectrum, and the data rate associated with this modulated portion is the available bandwidth of the remote spectrum block being modulated Compatible with.

  A method according to one embodiment is the step of dividing a data stream into a plurality of substreams, each substream being associated with a respective spectral fragment and having a bandwidth and compatibility with the respective spectral fragment. Each having at least one data rate, modulating each of the substreams to provide a modulated signal adapted for transmission by each spectral fragment, and each of the at least one carrier signal Upconverting the modulated signal into spectral fragments, and substreams contained within the upconverted modulated signal are demodulated and combined at the receiver to thereby recover the data stream You can They are adapted to.

  An apparatus according to an embodiment is a duplexer for splitting a data stream into a plurality of substreams, each substream associated with a respective spectral fragment and a bandwidth of the respective spectral fragment. And a plurality of modulators having a data rate compatible with each, each modulator providing a modulated signal adapted for transmission by a respective spectral fragment A plurality of modulators configured to modulate respective substreams and at least one upconverter for upconverting the modulated signal into respective spectral fragments of at least one carrier signal Included in the upconverted modulated signal. Stream, thereby being adapted to be demodulated and combined at the receiver to recover the data stream.

  The division function of the method or apparatus is the step of encapsulating successive portions of the data stream into the payload portion of each encapsulated packet, each successive portion of the data stream being a respective encapsulated packet A step associated with each sequence number included in the header portion of the first and a step of selectively routing the encapsulated packet towards the demodulator.

  Selective routing may be based on encapsulated packet routing according to any of a random routing algorithm, a round robin routing algorithm, a customer specified algorithm, a service provider specified algorithm, etc. Each substream is associated with a respective weight.

  The various substreams may be one or more transponders in a satellite communication system, one or more microwave links in a microwave communication system, and / or one or more wireless channels in a wireless communication system. Can be modulated and up-converted into a carrier signal for transmission over the network.

  In various embodiments, the encapsulated packet is routed multiple times to add resiliency / redundancy.

  The teachings of the present invention can be readily understood by considering the following detailed description in conjunction with the accompanying drawings, in which:

1 is a block diagram illustrating a communication system according to one embodiment. FIG. 5 graphically illustrates spectrum allocation useful for understanding the present embodiment. 1 is a high-level block diagram of a general purpose computing device suitable for use with various embodiments. FIG. 3 is a flow diagram of a method according to one embodiment. 3 is a flow diagram of a method according to one embodiment. 3 is a flow diagram of a method according to one embodiment. 1 is a block diagram of a communication system according to one embodiment. 1 is a block diagram of a communication system according to one embodiment. 1 is a block diagram of a communication system according to one embodiment. 1 is a block diagram of a communication system according to one embodiment. 1 is a block diagram of a communication system according to one embodiment. 1 is a block diagram of a communication system according to one embodiment. FIG. 3 is a high-level block diagram of a slicer / demultiplexer suitable for use with various embodiments. 3 is a flow diagram of a method according to one embodiment.

  To facilitate understanding, identical reference numerals have been used, where possible, to designate identical elements that are common to the figures.

  The invention is mainly described in the context of a satellite communication system. However, those skilled in the art and those knowledgeable from the teachings herein, the present invention is also applicable to any system that benefits from flexible spectrum allocation, such as microwave communication systems, wireless communication systems, etc. Will understand.

  One embodiment consolidates multiple fragmented blocks of the wireless spectrum into one contiguous virtual block such that the cumulative bandwidth is approximately equal to the sum of the bandwidths of the constituent blocks. To provide efficient and general-purpose technology. Fragmented blocks are optionally separated from each other by blocks of spectrum, such as guard blocks, blocks owned by others, and blocks banned by regional or national wireless spectrum supervisors.

  FIG. 1 shows a block diagram of a communication system that benefits from various embodiments. The communication system 100 of FIG. 1 includes a virtual spectrum aggregator transmitter 110, a power amplifier 120, a satellite uplink 130, a satellite 140, a satellite downlink 150, a virtual spectrum aggregator receiver 160, and optionally a control module 170. • Includes two-point links. Data transmitted over the point-to-point link is provided as a data stream packet D, such as a 188 byte transport stream (TS) packet, a 64-1500 byte Ethernet packet, and the like. The particular packet structure, the data carried within the packet structure, etc. are easily adapted to the various embodiments described herein.

The input data stream D is received by the virtual spectrum aggregation transmitter 110 and processed by the slicer / demultiplexer 111 to provide _N substreams (D ₀ ... D _N−1 ), where N Corresponds to a number of spectral fragments denoted as S ₀ , S ₁ etc. to S _N−1 .

As shown in FIG. 1, N = 3, so the slicer / demultiplexer 111 will (by way of example) input data stream D into three substreams shown as D ₀ , D ₁ , and D _2. Are sliced, multiplexed, and / or divided.

Each of the substreams D ₀ , D ₁ , and D ₂ is coupled to a respective modulator 112 (ie, modulators 112 ₀ , 112 ₁ , and 112 ₂ ). Each of the modulators 112 ₀ , 112 ₁ , and 112 ₂ has a respective sub-frame to provide a corresponding modulated signal as carried by the respective spectral fragment S ₀ , S ₁ , and S ₂ . Modulate streams D ₀ , D ₁ , and D ₂ .

Modulator 112 may include modulators that have the same characteristics, such as waveform types, constellation maps, forward error correction (FEC) setting characteristics, or the like. Each modulator is optimized according to a specific type of traffic (eg, streaming media, non-streamed data, etc.), specific channel conditions associated with its corresponding spectral fragment S _i , and / or other criteria Can do.

Generally speaking, the amount of data allocated to any substream D _i by the slicer / demultiplexer 111 is proportional to the data carrying capacity of the corresponding spectral fragment S _i . In various embodiments, each of the substreams D _i includes the same amount of data, while in other embodiments, the various substreams D _i can include different amounts of data.

As shown in FIG. 1, the first modulator 112 ₀ provides a 6 MHz signal associated with the first spectral fragment S ₀ , and the second modulator 112 ₁ provides the second spectral fragment S 0. providing 1MHz signal associated with _one, the third modulator 112 ₂ provides a signal of 1MHz associated with the third spectral fragment _{S 2.}

  A frequency multiplexer (ie, signal combiner) 113 operates to combine the modulated signals to produce a combined modulated signal Sc, which is up to provide a modulated carrier signal C. Modulated into a carrier signal by converter 114. Multiple frequency multiplexer / signal combiners 113 may be used to multiplex each group of modulated signals to be transmitted over common transponders, microwave links, wireless channels, etc. Note that you can.

  In the embodiment of FIG. 1, the spectrum associated with the modulated carrier signal C is logically or actually divided into a plurality of spectral fragments used to convey the modulated data substream. The Spectral fragment allocation tables or other data structures indicate which spectral fragments are specified, which spectral fragments (which data substreams) are used, and which spectral fragments are available Used to track. Generally speaking, each transponder / transmission channel can be divided into multiple spectral fragments or regions. Each of these spectral fragments or regions can be assigned to a particular data substream. Each of the data substreams can be modulated according to a unique or common modulation scheme.

  As shown in FIG. 1, since a single satellite transponder is used, all modulated signals can be combined by a frequency multiplexer 113 prior to upconversion and transmission over a single satellite channel. In various embodiments, multiple transponders can be used in one or more satellites. In these embodiments, only those modulated signals transmitted via a common transponder within the satellite are combined and converted together. In various embodiments, the modulated waveforms are transmitted independently.

The modulated carrier signal C generated by the upconverter 114 is amplified by the power amplifier 120 and transmitted to the satellite 140 via the satellite uplink 130. Satellite 140 transmits a modulated carrier signal comprising modulated substreams D ₀ , D ₁ , and D ₂ to hygiene downlink 150, which propagates the signal to virtual spectrum aggregator receiver 160.

The virtual spectrum aggregator receiver 160 includes a downconverter (165) that downconverts the combined spectral fragment signal Sc ′ from the received carrier signal C ′, and a spectral fragment from the combined spectral fragment signal Sc ′. And a frequency demultiplexer (164) that operates to separate S ₀ ′, S ₁ ′, and S ₂ ′.

Each of the spectral fragments S ₀ ′, S ₁ ′, and S ₂ ′ is coupled to a separate demodulator (ie, demodulators 162 ₀ , 162 ₁ , and 162 ₂ ). In order to provide corresponding demodulated substreams D ₀ ′, D ₁ ′ and D ₂ ′, each of the demodulators 162 ₀ , 162 ₁ , and 162 ₂ has its respective spectral fragment S ₀ ′, S demodulating the ₁ 'and _{S 2'.}

In order to generate an output data stream D ′ representing the input data stream D initially processed by the virtual spectrum aggregator transmitter 110, the demodulated substreams D ₀ ′, D ₁ ′, and D ₂ ′ are Are processed by the coupler 161. Note that each demodulator 162 operates in a manner that is compatible with its corresponding modulator 112.

As an option, the virtual spectrum aggregator receiver 160 includes buffers 166 ₀ , 166 ₁ , and 166 ₂ that provide elastic elastic buffering capabilities for the various demodulated substreams, so that the various substreams Coordination errors caused by different propagation delays associated with can be avoided before combining the substreams. The buffer belonging to 166 is shown as a functional element located between the demodulator (162) and the combiner 161. In various embodiments, the buffer 166 or their functional equivalent is included in the coupler 161. For example, combiner 161 may include a single buffer that receives data from all of the demodulators (162) and then repositions the data as output stream D ′. The packet ID and / or other information in the substream can be used for this purpose.

  Optional control module 170 may be an element management system (EMS), a network management system (NMS), and / or other suitable for use in managing network elements that implement the functionality described herein with respect to FIG. Interact with the management or control system. The control module 170 can be used to configure various modulators, demodulators, and / or other circuitry within the elements described herein with respect to FIG. Further, the control module 170 may be located remotely with respect to the elements controlled thereby, may be located adjacent to the transmission circuit, may be located adjacent to the receiver circuit, etc. It may be located in any place. The control module 170 can be implemented as a general purpose computer programmed to perform certain control functions as described herein. In one embodiment, control module 170 configures and / or operates virtual spectrum aggregator transmitter 110 and virtual spectrum aggregator receiver 160 via first control signal TXCONF and second control signal RXCONF, respectively. Configure. In this embodiment, multiple control signals can be provided for multiple transmitters and receivers.

FIG. 2 shows a graphical representation of spectrum assignment that is helpful in understanding this embodiment. Specifically, FIG. 2 graphically illustrates a 36 MHz spectrum allocation, where a first customer is allocated a first portion 210 of the spectrum, illustratively a single 10 MHz block, and a second Customer is assigned a second portion of spectrum 220, illustratively a single 8 MHz block, and a third customer is assigned a third portion of spectrum 230, illustratively a single 10 MHz block And the fourth customer has three discontinuous spectra including a fourth portion 240 of the spectrum, illustratively a first 1 MHz block 240 ₁ , a second 1 MHz block 240 ₂ , and a 6 MHz block 240 ₃ A block is allocated.

  In various embodiments described herein, the data stream associated with the fourth customer is split into two different 1 MHz spectral fragments in a single 6 MHz spectral fragment, each of the splits. Is processed in essentially the same manner as described above with respect to FIG.

  FIG. 3 illustrates a high-level block diagram of a general purpose computing device 300 suitable for use with the various embodiments described herein. For example, the computing device 300 shown in FIG. 3 is suitable for implementing the various transmitter processing functions, receiver processing functions, and / or management processing functions described herein. Can be used to perform

  As shown in FIG. 3, computing device 300 includes input / output (I / O) circuitry 310, processor 320, and memory 330. Processor 320 is coupled to each of I / O circuit 310 and memory 330.

  The memory 330 is shown to include a buffer 332, a transmitter (TX) program 334, a receiver (RX) program 336, and / or a management program 338. The particular program stored in the memory 330 depends on the functionality implemented using the computing device 300.

In one embodiment, the slicer / demultiplexer 111 described above with respect to FIG. 1 is implemented using a computing device, such as computing device 300 of FIG. Specifically, the processor 320 performs the various functions described above with respect to the slicer / demultiplexer 111. In this embodiment, I / O circuit 310 receives an input data stream D from a data source (not shown) and provides _N substreams (D ₀ ... D _N−1 ) to demodulator 112. To do.

In one embodiment, the combiner 161 described above with respect to FIG. 1 is implemented using a computing device, such as computing device 300 of FIG. Specifically, the processor 320 performs the various functions described above with respect to the combiner 161. In this embodiment, I / O circuit 310 receives demodulated substreams D ₀ ′, D ₁ ′, and D ₂ ′ from demodulator 162 (optionally through buffer 166) and provides virtual spectrum An output data stream D ′ representing the input data stream D originally processed by the aggregator transmitter 110 is provided.

  In one embodiment, the optional control module 170 described above with respect to FIG. 1 is implemented using a computing device, such as computing device 300 of FIG.

  Although primarily shown and described as having a particular type and arrangement of components, it will be appreciated that other suitable types and / or arrangements of components may be used for computing device 300. The computing device 300 can be implemented in any manner suitable for implementing the various functions described herein.

  It is understood that the computer 300 shown in FIG. 3 provides a general architecture and functionality suitable for implementing the functional elements described herein and / or portions of the functional elements described herein. Will be done. The functions shown and described herein may be implemented in software and / or hardware using, for example, a general purpose computer, one or more application specific integrated circuits (ASICs), and / or other hardware equivalents. can do.

  It is contemplated that some of the steps described herein as a software method may be implemented in hardware, for example, as a circuit that cooperates with the processor to perform the various method steps. Some of the functions / elements described herein can be implemented as a computer program product, and computer instructions are invoked by the methods and / or techniques described herein when processed by a computer. Configure the operation of the computer as provided or otherwise provided. Instructions for invoking the method of the present invention are stored in a fixed or removable medium, transmitted via a data stream on a broadcast or other signal carrying medium, transmitted via a tangible medium, and / or instructions Can be stored in a memory in a computing device that operates according to

  FIG. 4 shows a flow diagram of a method according to one embodiment. Specifically, the method 400 of FIG. 4 is suitable for processing a data stream D for transmission, as described above with respect to FIG.

  At step 410, a data stream is received that includes data from one or more customers, such as by virtual spectrum aggregation transmitter 110.

  At step 420, the received data stream is sliced into N substreams, and each substream is associated with a respective spectral fragment. Referring to box 425, the process of slicing the data stream into substreams may be performed according to the following criteria: fixed size, variable size, various slicing methods and / or per customer, per fragment, data type. Any other combination of criteria can be implemented, either alone or in any combination.

  At step 430, each of the substreams is modulated using a respective modulator. Referring to box 435, the demodulator can be optimized for data type and optimized for channel conditions, they share common characteristics, they have various / different characteristics, and so on.

  In optional step 440, one or more modulated substreams are to be transmitted using the same transponder or transmission channel, and these modulated substreams are combined.

  In step 450, the modulated substream is upconverted and transmitted. Referring to box 455, the upconversion / transmission process may be in a satellite communication system, a microwave communication system, a wireless communication system / channel, or other medium.

  FIG. 5 shows a flow diagram of a method according to one embodiment. Specifically, the method 500 of FIG. 5 is suitable for processing one or more received substreams, as described above with respect to FIG.

  At step 510, one or more modulated substreams are received and downconverted. Referring to box 515, one or more modulated substreams may be received via a satellite communication scheme, a wireless communication system, a wireless communication system / channel, or other medium.

  At step 520, the substreams previously combined at the transmitter are separated to provide individual substreams, and at step 530, each of the individual substreams is used using a respective appropriate demodulator. Demodulated.

  At step 540, one or more of the demodulated substreams are selectively delayed so that the resulting demodulated data stream can be temporarily adjusted.

  At step 550, the demodulated and selectively delayed substream provides a resulting data stream, such as a data stream D ′ representing the input data stream D that was originally processed by the virtual spectrum aggregator transmitter. To be combined.

  FIG. 6 shows a flow diagram of a method according to one embodiment. In particular, the method 600 of FIG. 6 is suitable for configuring various transmitter and receiver parameters in accordance with various embodiments.

  At step 610, a request is received for transmission of customer data. Referring to box 615, the request is a specified bandwidth, a specified data rate, a specified data type, a specified modulation type, and / or a bandwidth and / or service requirement associated with a customer data transmission request. Other information describing the can be provided.

  At step 620, a determination is made regarding a spectrum allocation suitable to meet customer data transmission requirements.

  At step 630, an optional decision is made regarding whether a particular spectrum-related criterion is suitable to meet customer data transmission requirements. Referring to box 635, such spectrum-related criteria may include a minimum bandwidth block size, a continuous bandwidth block requirement, and / or other criteria.

  At step 640, available spectral fragments are identified. Referring to box 645, identification of available spectral fragments can be made with respect to an allocation table, a management system, and / or other sources of such information. In one embodiment, the allocation table defines the spectrum allocation associated with each customer served by the satellite communication system, ie, each customer's bandwidth allocation, transponder (s) that support the bandwidth, Such as satellite (s) that support transponder (s). In addition, the available spectral fragments are defined with respect to the size and spectral region of each transponder of each satellite.

  At step 650, available spectrum fragments are allocated to satisfy customer data transmission requirements. Referring to box 655, available spectral fragments are allocated as available, optimized for customers, optimized for carriers, optimized to reduce the number of spectral fragments, resiliency or redundancy. Can be optimized to provide degrees and / or optimized based on other criteria.

  At step 660, the transmitter / receiver system supports customer data transmission requests and adapts to any changes to spectrum fragment allocation for the requesting customer and / or other customers. Configured to provide the correct number and type of modulator / demodulators. That is, it may be appropriate to change the spectrum fragment assignments of multiple customers based on optimization and / or other criteria to support and optimize for specific customers, service providers, etc. .

  At step 670, billing data, service contracts, etc. are updated appropriately. At step 680, the system configuration, supply, and / or other management data is updated.

  In various embodiments, spectral fragments available on different satellite transponders and / or different satellites are aggregated to form a virtual contiguous block. In other embodiments, the full bandwidth of multiple transponders is used to support high data rate pipes (eg, OC-3 / 12c) over satellite links.

7-9 illustrate block diagrams of communication systems according to various embodiments. Each of the various components in the communication system shown in FIGS. 7-9 essentially function in the same manner as described above with respect to the corresponding components in the communication system of FIG. For example, in each of the embodiments of FIGS. 7-9, the input data stream D is received by the virtual spectrum aggregation transmitter 110 to provide _N sub-streams (D ₀ ... D _N−1 ) Processed by slicer / demultiplexer x11 (711, 811, 911), each of the N substreams is modulated by a respective modulator x12 (712, 812, 912). Other differences and similarities between the various figures will now be described in more detail.

  FIG. 7 illustrates a single transponder embodiment in which a single transponder is used to carry each of a plurality of data streams denoted as streams A, B, C, and D. FIG. 7A shows the uplink portion of the system, while FIG. 7B shows the downlink portion of the system.

Referring to FIG. 7A, data streams A, B, and to generate respective modulated streams that are combined by a _first signal combiner 113 ₁ to provide a combined modulated signal ABC. C is modulated by a respective modulator 712.

Next, respective modulators 712 (ie, modulators 712 ₀ , 712 ₁ , and 712) are provided to provide corresponding modulated signals carried by the respective spectral fragments S ₀ , S ₁ , and S ₂ . ₂ ) Data stream D is processed by slicer / demultiplexer 711 to provide _N sub-streams (D ₀ ... D _N−1 ) modulated by Corresponding modulated signals are combined by a _second signal combiner 7132 to provide a combined modulated signal DDD. This is combined with the modulated signal ABC by the third signal combiner 713 _3. The resulting combined modulated signal is converted by upconverter 714 to generate carrier signal C that is amplified by power amplifier 720 and transmitted to satellite 740 via satellite uplink 730. .

Referring to FIG. 7B, satellite 740 transmits a modulated carrier signal including modulated streams A through D to sanitary downlink 750 that propagates the signal to downconverter 765. Down-converted signal is processed by the frequency demultiplexer 764 ₃ that operates to separate the signal into signal components of the ABC and DDD.

ABC signal components are separated by a second frequency demultiplexer 764 ₁ to recover the modulated signals are then demodulated by respective demodulators 752.

To recover the respective modulated signal demodulated by a demodulator 752, DDD signal components are separated by a third frequency demultiplexer 764 _2.

The demodulated substreams D ₀ ′, D ₁ ′, and D ₂ ′ are processed by a combiner 761 to generate an output data stream D ′ that represents the input data stream D. Note that each demodulator 162 operates in a manner that is compatible with its corresponding modulator 112.

  FIG. 8 shows an embodiment with two transponders, where the first transponder is not only two of the three substreams associated with data stream D, but also multiples shown as streams A, B, and C. The second transponder is used to convey a plurality of data streams denoted as E and F as well as a third substream associated with data stream D. Is done. FIG. 8A shows the uplink part of the system and FIG. 8B shows the downlink part of the system.

  Referring to FIG. 8A, data streams A, B, C, E, and F are modulated by respective modulators 812 to produce respective modulated streams.

  Data streams E and F are modulated by respective modulators 812 to produce respective modulated signals.

The respective modulators 812 (ie, modulators 812 ₀ , 812 ₁ , and 812) are then provided to provide corresponding modulated signals carried by the respective spectral fragments S ₀ , S ₁ , and S ₂ . ₂ ), the data stream D is processed by a slicer / demultiplexer 811 to provide _N sub-streams (D ₀ ... D _N−1 ) modulated by

In order to provide a combined modulated signal ABC, the modulated signals associated with data streams A, B, and C are combined by a _first signal combiner 8131.

The modulated signals associated with substreams D ₀ and D ₁ are combined by a _second signal combiner 8132 to provide a combined modulated signal D ₁₂ .

Then, first 813 ₁ and the second 813 ₂ of the modulated signal in combination generated by the signal combiner is combined by the third signal combiner 813 _3, the first carrier signal C1 It is converted by the _first upconverter 814 ₁ to generate.

Modulated signal associated with the sub-stream D ₃ and stream E and F, are combined by a fourth signal combiner 813 _4, the second upconverter 814 ₂ to produce a second carrier signal C2 Converted.

The C1 and C2 carrier signals are combined by the _fourth signal combiner 8134, amplified by the power amplifier 820, and transmitted to the satellite 840 via the respective transponders (A and B) of the satellite uplink 830. Is done.

Referring to FIG. 8B, satellite 840 transmits two modulated carrier signals, including streams A to F, modulated via respective transponders (A and B) to sanitary downlink 850, which transmits the signals. Propagate to downconverter 865. Down-converted signal is separated into its two carrier signals by a frequency demultiplexer 864 _4. The two carrier signals are used to generate various output data streams A ′ to F ′ representing input data streams A to F, various demultiplexers belonging to 864, demodulator belonging to 862, and combiner 861. Is processed using.

FIG. 9 shows that one satellite (940 ₁ ) is used to carry multiple data streams, shown as streams A, B, and C, along with two of the three substreams associated with data stream D. Figure 2 shows an embodiment with two satellites. The second satellite (940 ₂ ) is used to carry a plurality of data streams, denoted as E and F, along with a third substream associated with data stream D. FIG. 9A shows the uplink portion of the system, and FIG. 9B shows the downlink portion of the system.

Referring to FIG. 9A, data streams A, B, C, E, and F are illustrated with the exception that the two carrier signals are not combined for transmission through the respective transponders of a single satellite. It is processed in essentially the same manner as described above for 8A. Rather, FIG. 9 shows two carrier signals amplified by separate power amplifiers (920 ₁ and 920 ₂ ) and transmitted to satellites 940 ₁ and 940 ₂ using uplinks 930 ₁ and 930 ₂ , respectively. ing.

  Referring to FIG. 9B, two satellites 940 transmit their respective modulated carrier signals, including modulated streams A through F, via their respective downlinks 950, which in turn are transmitted to their respective downconverters. 965. The two downconverted carrier signals are demultiplexer (964), demodulator (962), and combiner (to generate output data streams A ′ to F ′ representing input data streams A to F). 961).

  FIG. 10 shows a high-level block diagram of a slicer / demultiplexer suitable for use with the various embodiments described herein. Specifically, the slicer / demultiplexer 1000 of FIG. 10 includes a packet encapsulator 1010, a master scheduler 1020 that includes a buffer memory 1022, and a plurality of slave schedulers 1030 that include a buffer memory 1032.

  Packet encapsulator 1010 operates to encapsulate packets received from data stream D into a packet structure having a predefined or normalized format. Although various encapsulated packet formats can be used, it is important to configure the combiner on the downlink side of the system to combine the packets according to the encapsulation format used by the slicer / demultiplexer on the uplink side of the system. is there.

  In one embodiment, the encapsulated packet comprises a 188 byte packet having a 185 byte payload section and a 3 byte header section. The packet encapsulator 1010 extracts a continuous 185 byte portion from the original data stream D and encapsulates each extracted portion to form an encapsulated packet (EP). Since the header portion of each encapsulated packet stores the user sequence number associated with the payload data, the contiguous 185 byte portion of the data stream is re-created by the combiner as described above with respect to the various figures. Can be built.

  In one embodiment, the user sequence number is continuously incremented and includes a 14-bit number used to stamp the encapsulated packet provided by the packet encapsulator 1010. In one embodiment, the header portion of the packet provided by the packet encapsulator 1010 stores a hexadecimal number 47 (ie 47h) followed by two zero bits followed by 14 bits associated with the user sequence number. Of bytes.

  If the overall data rate being conveyed is higher, a larger sequence number field (eg 24 or 32 bits) can be used. The size of the sequence number field is related to the amount of buffering that occurs at the receive combiner element described in the various figures above. The size of the buffer is then related to the ratio of the maximum substream bandwidth to the minimum substream bandwidth. Thus, various embodiments adjust the sequence number field size (and resulting overhead) based on the total total bandwidth and / or the ratio of the maximum and minimum bandwidth substreams. be able to.

  In various embodiments, more or less than 188 bytes are used to construct the encapsulated packet. In various embodiments, more or less than 3 bytes are used to construct the encapsulated packet header. For example, a larger user sequence number can be used by assigning additional header bits to the user sequence number. In this case, the possibility of processing two encapsulated packets having the same sequence at the receiver is reduced.

  In the embodiment described herein, a fixed packet size of 188 bytes is used for encapsulated packets. However, in various alternative embodiments, different fixed size packets and / or different variable size packets are compatible with the input interfaces of the respective modulators where such packet sizes are used for their substreams. As long as it can be used for different substreams.

  The master scheduler 1020 routes the encapsulated packet to various slave schedulers 1030. Slave scheduler 1030 then routes those packets to the respective output ports of the slicer / demultiplexer, thereby illustratively providing each substream to a modulator or other component.

  Generally speaking, each slave scheduler 1030 accepts packets that match the bandwidth of the spectrum fragment assigned to that scheduler. Thus, a slave scheduler serving a 1 MHz spectrum fragment channel accepts packets at a data rate approximately 1/10 that of a slave scheduler serving a 10 MHz spectrum fragment or region.

  The master scheduler 1020 communicates with the slave scheduler 1030 to identify which slave scheduler 1030 can (or should) receive the next encapsulated packet. Optionally, master scheduler 1020 receives status and other management information from slave scheduler 1030, and some of this status information can be propagated to various management entities (not shown).

  In one embodiment, slave scheduler 1030 provides a control signal to master scheduler 1020 that indicates the ability to accept packets. In one embodiment, master scheduler 1020 assigns packets to slave scheduler 1030 in a round robin fashion. In one embodiment, if a particular transmission channel or spectral region is preferred based on customer and / or service provider requirements, the allocation of encapsulated packets by the master scheduler 1020 may be used to service those preferred transmission channels. The slave scheduler 1030 is weighted to choose to provide more encapsulated packets.

  In one embodiment, each of the slave schedulers is associated with other indicators of channel capacity associated with a predefined bandwidth or corresponding spectral fragment. In this embodiment, the master scheduler 1020 routes packets according to the weighted assignment of each slave scheduler 1030.

  Generally speaking, the master scheduler routes packets according to one or more of a random routing algorithm, a round robin routing algorithm, a customer specified algorithm, and a service provider specified algorithm. Such routing can be accommodated by associating a weighting factor with each modulator, spectrum fragment, communication channel, etc. (eg, transponder, microwave link, wireless channel, etc.). For example, preferred spectral fragments include fragments having a minimum or maximum size, fragments associated with a relatively low error channel or relatively high error channel, fragments associated with a preferred communication type (eg, satellite, microwave link, Wireless network, etc.), fragments associated with the preferred customer, etc. Other means of weighting channels, communication systems, spectral regions, etc. may also be used in various embodiments.

  FIG. 11 shows a flow diagram of a method according to one embodiment. In step 1110, a packet is received from data stream D. At step 1120, the received packet is encapsulated. Referring to box 1125, the packet may include a 185 byte payload and a 3 byte header packet. Other header formats with different sequence number field sizes and / or additional control information may be used within the context of this embodiment.

  At step 1130, the encapsulated packet is buffered by way of example, by a master scheduler 1020, a separate buffer (not shown) in the packet encapsulator 1010, or the like.

  At step 1140, the encapsulator packet is forwarded (or made to forward) by the master scheduler 1020 to the slave scheduler 1030.

  In various embodiments described herein, each encapsulated packet is coupled to a respective modulator as part of a respective substream. However, in embodiments configured to provide increased data resiliency and / or backup, encapsulated packets can be combined into multiple modulators as part of multiple respective substreams. . In these embodiments, the sequence number associated with the encapsulated packet remains the same.

  In these embodiments, the receiver processes the first encapsulated packet (or error-free encapsulated packet) with the appropriate sequence number and ignores other packets with the same sequence number. . That is, when reordering the encapsulated packets at the receiver, those encapsulated packets having a sequence number that matches the sequence number of the recently ranked encapsulated packet are discarded. Encapsulated packets that have the same sequence number as the encapsulated packet processed thousands of packets ago because the sequence number is periodic or repeated (eg, every 16384 encapsulated packets for a 14-bit sequence number) Should be dropped or discarded as redundant because it may be a duplicate of its previously processed encapsulated packet.

  The various embodiments described herein provide dynamic spectral aggregation of blocks of distant spectra so that as customer bandwidth requirements change, the spectrum may increase or decrease from existing spectrum allocations. Can be. In addition, small or isolated spectral blocks (ie, spectral blocks that are too small to serve generally) can be effectively combined to form larger bandwidth blocks.

  The above embodiments provide many advantages, including improved system resiliency, since the loss of one spectral fragment will not cause a complete loss of service. Furthermore, if spectrum fragments are mapped across multiple transponders, the loss of one transponder will not result in a complete loss of service, but rather a service within an acceptable quality range (graceful).・ Degradation) is provided. Older / existing schemes that utilize continuous spectrum can use only one transponder that can be a single point of failure.

  Various advantages of the embodiments include not only the ability to use isolated spectral fragments that would otherwise be too small to use, but also significantly higher spectral usage efficiency. Various embodiments apply to satellite applications, point-to-point wireless links such as those used for bent pipe SatCom applications, wireless backhaul infrastructure provided using microwave towers, etc. can do.

  Various embodiments provide “pay-” for service providers and consumers because bandwidth is allocated by “adding” additional bandwidth blocks to those bandwidth blocks already in use. “As-you-grow” provides a mechanism that can drive the business model.

  In various embodiments, a single transponder of the satellite system is used to propagate a carrier signal that includes a plurality of modulated substreams, each of the modulated substreams having its respective spectral fragment. Occupy space. In other embodiments, multiple carrier signals are propagated through respective transponders.

  In various embodiments, a single microwave link in a microwave communication system is used to propagate a carrier signal that includes multiple modulated substreams, with each modulated substream being its respective Occupies the spectral fragment region. In other embodiments, the plurality of carrier signals are propagated via respective microwave links.

  In various embodiments, a single wireless channel in a wireless communication system is used to propagate a carrier signal that includes multiple modulated substreams, each modulated substream having its respective spectrum. Occupies the fragment area. In other embodiments, the plurality of carrier signals are propagated via respective wireless channels.

  While the foregoing has been described with reference to various embodiments of the present invention, other and further embodiments of the invention may be devised without departing from the basic scope of the invention. Many other various embodiments that incorporate these teachings can be readily devised. Accordingly, the proper scope of the invention should be determined according to the appended claims.

Claims (10)

Dividing an incoming data stream into a plurality of output substreams, each of the output substreams being associated with a respective spectral fragment and the bandwidth of the respective spectral fragment Having a data rate compatible with the width, step (420);
Modulating (430) each of the output substreams to provide a modulated signal adapted for transmission via the respective spectral fragment;
Upconverting (440) the modulated signal into respective spectral fragments of at least one carrier signal;
Including
Substreams contained within the upconverted modulated signal are adapted to be demodulated and combined at a receiver to recover the data stream;
Method.   Combining (440) two or more of the modulated substreams to form a respective combined substream, wherein each of the combined substreams is a total of combined substreams. The method of claim 1, further comprising the step of being modulated into a modulated signal adapted for transmission over a spectral fragment having a bandwidth compatible with an effective data rate.   The method of claim 1, further comprising transmitting (450) the carrier signal over a respective channel in a communication system.   The method of claim 3, wherein the one or more carrier signals are supported by respective transponders in a satellite communication system.   4. The method of claim 3, wherein each of the one or more carrier signals is supported by a respective microwave link in a microwave communication system. A duplexer for splitting an incoming data stream into a plurality of output substreams, each of said substreams being associated with a respective spectral fragment and a band of said respective spectral fragment A duplexer (111, 811) having a data rate compatible with the width;
A plurality of modulators, each modulator configured to modulate a respective output substream to provide a modulated signal adapted for transmission over the respective spectral fragment; A plurality of modulators (112, 812) configured in
An apparatus comprising at least one upconverter (114) for upconverting the modulated signal into respective spectral fragments of at least one carrier signal,
The substreams included in the upconverted modulated signal are adapted to be demodulated and combined at a receiver to recover the data stream;
apparatus. The duplexers (111, 811) are
An encapsulator for encapsulating successive portions of the data stream into a payload portion of each encapsulated packet, each of the successive portions of the data stream comprising a header of the respective encapsulated packet An encapsulator (1010) associated with each sequence number included in the portion;
A master scheduler (1020) for selectively routing packets encapsulated towards the demodulator;
The apparatus according to claim 6.   The apparatus of claim 7, wherein the master scheduler (1020) routes packets according to one of a random routing algorithm and a round robin routing algorithm. The master scheduler (1020) routes packets according to one of a customer specified algorithm and a service provider specified algorithm, and each substream is associated with a respective weight,
The apparatus according to claim 7. A computer readable medium comprising software instructions, said instructions being executed by a processor,
Splitting an incoming data stream into a plurality of output substreams, each of the output substreams being associated with a respective spectral fragment and the bandwidth of the respective spectral fragment Having a data transfer rate compatible with (420),
Modulating (430) each of the output substreams to provide a modulated signal adapted for transmission via the respective spectral fragment;
Performing (440) the step of up-converting the modulated signal into respective spectral fragments of at least one carrier signal;
The substreams contained within the upconverted modulated signal are adapted to be demodulated and combined at a receiver to recover the data stream;
Computer readable medium.

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